INGREDIENTS
1 stick
unsalted butter
7
bars semisweet chocolate12 oz. chopped, 7.5 oz. cut into 1-inch squares and the rest for garnish
1 1/2 cups
flour
1/4 cup
unsweetened cocoa powder
1 1/2 tsp
baking powder
1/4 tsp
salt
1 1/4 cups
(packed) light brown sugar
3
eggs, at room temperature
1 1/2 tsp
pure vanilla extract
30
marshmallows